1. FIELD OF THE INVENTION
This invention relates generally to medical appliances; and more particularly to devices such as syringes for withdrawing liquids from or injecting liquids into a patient's body.
2. PRIOR ART
My above-mentioned copending application and patent, whose disclosures and other recitations are hereby fully incorporated by reference herein, set forth in detail that a severe problem has developed in relation to all devices for withdrawing blood and other liquids from patients.
That problem relates to transmission of fatal and currently incurable diseases by exchange of body substances between people--and particularly transmission of such diseases to medical personnel who inadvertently touch needle tips after withdrawal from infected patients. The same problem is present with respect to devices for injecting liquids or other substances into patients.
The above-mentioned application and patent also discuss in detail numerous prior-art devices relating to guarding of needle tips. Such devices include a hypodermic needle commercially available from the firm ICU Medical, Inc., under the trade name "ICU High Risk Needle," as well as those disclosed and claimed in U.S. Pat. Nos. 4,592,744, 4,026,287, 4,631,057, 4,643,199, 4,573,976, 4,643,200, 4,425,120, 3,890,971, 2,876,770, 2,674,246 and 3,134,380.
My above-mentioned application and patent also disclose and claim my invention for use in guiding a cannula into place in a patient's body, to facilitate attachment of an intravenous tube for various well-known medical purposes. That invention is a safety device which thereafter protects medical personnel, trash-handling personnel and others from contact with portions of the device that have been within the patient.
I consider that invention to be an important advance in the field of medical safety. As disclosed in my above-mentioned application and patent, however, that invention left unresolved the related problem of infection by contact with syringe needles.